McPherson said she is now in "clinical remission but I would say I'm in utter wellness".
The news of her illness was also revealed in a chapter of her new book, titled Elle: Life, Lessons and How to Trust Yourself, under the heading Don't Sweat the Small Stuff.
The model, now 60, told Woman's Weekly that her doctor had recommended a mastectomy with radiation, chemotherapy, hormone therapy, plus reconstruction of her breast.
“It was a shock, it was unexpected, it was confusing, it was daunting in so many ways,” she told the magazine. “And it really gave me an opportunity to dig deep in my inner sense to find a solution that worked for me."
She said she spent several weeks deliberating over treatment options and sought advice from "32 doctors and experts" - but we don't know who they were or anything about their qualifications or experience.
Ultimately, she decided not to have chemotherapy and use what she described as “an intuitive, heart-led, holistic approach”.
“I came to the understanding that there was no sure thing and absolutely no guarantees. There was no ‘right’ way, just the right way for me," she wrote in her book, quoted in the magazine.
“I chose an holistic approach. Saying no to standard medical solutions was the hardest thing I’ve ever done in my life. But saying no to my own inner sense would have been even harder,” she added.
McPherson, who is also the founder of beauty and wellness firm WelleCo, said she was under the care of several specialists, including her primary doctor, a doctor of naturopathy, an holistic dentist, an osteopath and a chiropractor. It is not known what qualifications each member of her medical team holds.
Research suggests alternative treatments are linked to reduced survival rates.
McPherson added that she spent eight months in a rental property in Phoenix, Arizona, under her health team's care.
In her book, the model said her treatment decision received mixed reactions from her family, with one of her then teenage sons supportive of her not having chemotherapy, while the other "being more conventional, wasn't comfortable with my choice at all".
She added that he was still supportive even if he didn't agree with her, as was her former partner and the father of her sons, Arki Busson, who thought avoiding a traditional treatment plan was "extreme".
McPherson said she had previously found a cyst in one of her breasts in 2014, but it had turned out to be benign.
Cancer charity Macmillan says that if you are considering using alternative therapies, talk to your cancer doctor for advice and support.
Doctors are generally supportive of people using any complementary therapies that may help them cope better with their illness.
Complementary therapies are used alongside conventional breast cancer treatments such as chemotherapy. But doctors usually advise against using alternative therapies, which are used instead of medical treatment.
Macmillan adds that if you decide to use an alternative therapy, it is important to check it is safe: "Always check the credentials of the therapist. Alternative therapies can be expensive, and some can cause serious side effects. They can also make you feel unwell and be harmful to your health.
Cancer Research UK says: "Therapists and companies who promote alternative therapies can cause harm by convincing people an alternative therapy will cure them, when it can’t. This can be especially harmful if a person is also encouraged to give up their conventional cancer treatment."
Responding to the news of Elle Macpherson’s breast cancer diagnosis, Jane Murphy, clinical nurse specialist at Breast Cancer Now, said: “Each person’s breast cancer diagnosis is different, and as such the treatment they are recommended will be tailored to their individual situation and agreed by them and a team of breast cancer experts. Specialists base this on robust clinical evidence."